This invention relates to an electronic component cooling apparatus for cooling an electronic component such as an MPU or the like, and more particularly to an electronic component cooling apparatus of the type that a heat sink on which an electronic component is mounted is forcibly cooled by air fed from a fan unit.
An electronic component cooling apparatus of the type that a heat sink including a plurality of radiation fins and a fan unit are combined with each other has been conventionally known in the art, as disclosed in Japanese Patent Application Laid-Open Publication No. 268125/1994, Japanese Patent Application Laid-Open Publication No. 83873/1996, U.S. Pat. Nos. 5,519,574, 5,484,013, 5,452,181, 5,421,402, 5,251,101, 5,309,983 and the like.
Also, U.S. Pat. No. 5,615,998 discloses an electronic component cooling apparatus which is provided with an engagement structure including a plurality of engaging sections provided at a fan unit and a plurality of engaged sections provided at a heat sink and engaged with the engaging sections of the fan unit. The engaging sections and engaged sections are permitted to be engaged with each other by merely approaching a casing of the fan unit to the heat sink.
Such a conventional electronic component cooling apparatus as described above is typically constructed so that air discharged from a fan unit and heated by radiation fins is exhausted in all directions from a heat sink. Also, an electronic component cooling apparatus disclosed in each of U.S. Pat. No. 5,309,983, 5,519,574 (FIG. 3A), Japanese Utility Model Publication No. 23034/1990 and U.S. Design Pat. No. 403,760 includes a heat sink in which a plurality of radiation fins are arranged in parallel to each other while being spaced from each other at intervals, so that air is discharged in two directions in which the radiation fins extend. Such arrangement of the radiation fins in a manner to be parallel to each other facilitates manufacturing of the heat sink, to thereby substantially reduce manufacturing cost of the heat sink, leading to a reduction in price of the electronic component cooling apparatus. However, such arrangement of the radiation fins fails to contribute to an increase in cooling efficiency even when air is forcibly blown against the radiation fins using a fan unit.
Another electronic component cooling apparatus is disclosed in U.S. Pat. No. 5,740,014, which is constructed so as to aim at an improvement in cooling efficiency. In the electronic component cooling apparatus, a heat sink is formed with a plurality of parting slits in a manner to be perpendicular to all of plural radiation fins arranged in parallel to each other on a base of the heat sink, to thereby divide the radiation fins into fine or thin plate-like strips. Then, air is forcibly blown against the strips from an axial fan unit, to thereby aim to improve cooling efficiency. The parting slits also partially divide the base of the heat sink into sections. Also, in the electronic component cooling apparatus, the fan unit is fixed on the heat sink by means of screws.
Still another electronic component cooling apparatus is taught in Japanese Patent Application Laid-Open Publication No. 223816/1998, which is constructed in such a manner that a plurality of pin-like or bar-like radiation fins are integrally mounted on a base of a heat sink and the base is formed on an outer periphery thereof with a plurality of slits. A fan unit is fixed on the base of the heat sink by means of screws.
The above-described electronic component cooling apparatus taught in U.S. Pat. No. 5,740,014 wherein the radiation fins arranged in parallel to each other are divided into the strips fails to satisfactorily improve cooling efficiency. In the electronic component cooling apparatus, the fan unit is fixed on the heat sink by means of screws.
The electronic component cooling apparatus disclosed in U.S. Design Pat. No. 403,760 and briefly described above is provided with an engagement structure including a plurality of engaging sections provided at a fan unit and a plurality of engaged sections provided at a heat sink and engaged with the engaging sections, as in U.S. Pat. No. 5,615,998.